Skip to main content
Add a captcha challenge to your booking page to keep automated bots and malicious scripts from flooding your calendar with fake appointments. In Cal ID, the Enable captcha on Booking page feature is a vital security layer designed to protect your calendar from automated spam bots and malicious booking scripts.
Captcha is bot protection for your booking page: it verifies that a real person — not an automated script — is submitting the booking, so scrapers and bots can’t snatch slots or fill your schedule with junk.

​
Why use “Enable captcha on Booking page”?

  • Bot Mitigation: Prevents automated bots from flooding your schedule with fake appointments, ensuring your availability is reserved for real clients.
  • Protect Public Links: Essential for “Discovery Calls” or booking links that are openly accessible to web scrapers.
  • Prevent “Denial of Service” on Slots: Bots can be used to “snatch” every available slot in seconds to prevent others from booking. Captcha blocks these scripts.
  • Clean Data: Keeps your dashboard and connected CRM free from junk data and “trash” leads.

​
How to set it up

1

Log in to Cal ID

Log in to your Cal ID account.
2

Go to Event Types

Go to Event Types and open the event you want to change.
3

Navigate to Advanced

Click on the Advanced tab in the top navigation bar.
4

Toggle Captcha

Locate the Enable captcha on booking page option and switch it to ON.
5

Select Captcha Strength

Once enabled, a new dropdown field will appear labeled Select captcha strength. Choose the level that fits your needs:
  • Low: Minimal friction; only challenges highly suspicious traffic.
  • Medium: The standard balance between security and booker experience.
  • High: Strict verification; more likely to present an interactive challenge to every booker.
Advanced tab with the Enable captcha on booking page toggle switched on and the Select captcha strength dropdown open on Low, Medium and High

Balancing security against booker friction

6

Save

Click the blue Save button at the top right.

​
How it works for the booker

  • Frictionless Experience: Cal ID uses Cloudflare Turnstile. For most bookers, the check happens silently in the background without them having to do anything.
  • Interactive Challenges: If the booker’s browser behavior appears “bot-like,” the system presents a short interactive challenge that they must complete before clicking “Confirm Booking”.
  • Strength Impact: At High strength, the system is much more sensitive, which increases security but may cause slight delays for legitimate bookers.
If you are using Requires booker email verification alongside Captcha, your booking page will be highly secure. However, keep in mind that every extra step (Captcha + Email Verification) adds “friction.” For internal team links or private 1-on-1s, we recommend keeping these settings at Medium or Low to ensure a smooth booking flow.

​
Other booking form protections

Verify booker email

Require a verification code before a booking is confirmed.

Require or exclude email domains

Allow or block specific email domains at booking.

Disable adding guests

Keep meetings strictly one-on-one.

Add pre-booking questions

Collect the information you need before someone books.

Related topics

Verify Booker EmailRequire or Exclude Email DomainsDisable Adding GuestsAdd Pre-Booking Questions for Events